We will continue our multidisciplinary program of clinical research to improve the treatment of acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML). The chemotherapy innovations involve intensive and rotational therapy of chemotherapeutic agents in remission in patients with AML in attempt to maximize leukemia cytoreduction and minimize the development of drug resistance. In acute lymphocytic leukemia (ALL) the major chemotherapeutic thrust will relate to the development of modified and new programs for prognostic subcategories of ALL. Clinical pharmacologic studies of established agents as well as new agents will be conducted in parallel with the clinical therapeutic research.